Kusunoki S, et al. – The effectiveness of positron emission tomography/computed tomography (PET/CT) for the diagnosis of uterine sarcoma is examined in this study. In patients with magnetic resonance imaging (MRI) findings consistent with either uterine sarcoma or leiomyoma, PET/CT can reduce the false–positive rate by setting an optimal cutoff SUVmax of 7.5. Utilizing this cutoff can avoid unnecessary surgery.

Methods

• 24 patients assessed between January 2010 and March 2015 were retrospectively selected.
• All patients in whom uterine sarcoma was suspected based on contrast–enhanced magnetic resonance imaging (MRI) findings (heterogeneous, high signal intensity on T2–weighted images and/or high intensity on T1–weighted images) underwent PET/CT for further evaluation.
• Patients were divided into 2 groups based on postoperative pathological findings: uterine sarcoma (n = 15) and leiomyoma (n = 19).
• The maximum standardized uptake value (SUVmax) of all lesions was measured utilizing PET/CT; they figured the optimal cutoff value for diagnosing sarcoma.

Results

• In this study, they found median SUVmax for uterine sarcoma and leiomyoma was 12 and 4.1, respectively; these values were significantly different.
• An SUVmax of greater than 7.5 was able to exclude leiomyoma with 80.8% sensitivity and 100% specificity (area under the curve, 95.3%).
• A cutoff SUVmax of 7.5 yields 100% specificity, and a cutoff SUVmax of 4.4 yields a 100% negative predictive value (NPV).
• The combination of PET/CT and lactate dehydrogenase (LDH) levels had a sensitivity of 86.6%, specificity of 100%, positive predictive value of 100%, and an NPV of 90.4%.
• There was no connection between histopathology or International Federation of Gynecology and Obstetrics (FIGO) stage and 18–fluoro–2–deoxy–d–glucose uptake value on PET/CT was found.
• The surgical outcome trended toward a correlation with the SUVmax, although this was not statistically important.